Method and apparatus for supporting paging over an hs-dsch in cell_pch and ura_pch states

ABSTRACT

A method and apparatus for paging a wireless transmit/receive unit (WTRU) in a CELL_PCH and URA_PCH states are disclosed. A WTRU may send an indication of an enhanced paging channel (PCH) capability of receiving a high speed downlink shared channel (HS-DSCH) in CELL_PCH and URA_PCH states, for example, in a CELL UPDATE message, a URA UPDATE message, or a UTRAN MOBILITY INFORMATION CONFIRM message. A drift radio network controller (DRNC) may receive an indication whether the WTRU has an enhanced PCH capability from a serving RNC and page the WTRU based on the indication. An RNC may page the WTRU over both an HS-DSCH and a PCH/secondary common control physical channel (S-CCPCH) if a WTRU capability is not known. The WTRU may monitor both an HS-DSCH and a PCH/S-CCPCH. The WTRU may configure reception over an HS-DSCH based on the capability of the SRNC or configuration from the network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application Nos.60/955,217 filed Aug. 10, 2007, 60/969,832 filed Sep. 4, 2007, and60/986,154 filed Nov. 7, 2007, which are incorporated by reference as iffully set forth.

FIELD OF INVENTION

This application is related to wireless communications.

BACKGROUND

Four radio resource control (RRC) states are defined in the conventionalthird generation partnership project (3GPP) specifications. Those RRCstates are CELL_DCH state, CELL_FACH state, CELL_PCH state, and URA_PCHstate. Improvements on the conventional CELL_FACH and CELL/URA_PCHstates have been introduced to the 3GPP specifications to enhance theoverall quality of experience (QoE) perceived by end users. TheCELL_FACH and CELL_URA_PCH improvements attempt to reduce statetransition delays and overall signaling latencies by using high speeddownlink packet access (HSDPA) resources in the CELL_FACH andCELL/URA_PCH states.

With an introduction of the enhanced CELL_FACH state, a high speeddownlink shared channel (HS-DSCH) may be used in the CELL_FACH state.The HS-DSCH replaces the conventional forward access channel (FACH). Awireless transmit/receive unit (WTRU) with enhanced FACH capability willreceive downlink messages over the HS-DSCH. For example, downlink RRCmessages, (e.g., CELL UPDATE CONFIRM and URA UPDATE CONFIRM messages),will be sent to the WTRU over the HS-DSCH in the CELL_FACH state.

With an introduction of the enhanced CELL/URA_PCH states, the HS-DSCHmay also be used in the CELL_PCH and URA_PCH states. The HS-DSCHreplaces the conventional FACH and PCH, and dedicated control channel(DCCH) and dedicated traffic channel (DTCH) may be transmitted to theWTRU in the CELL_PCH state over the HS-DSCH. A WTRU with enhanced PCHcapability will receive paging messages over the HS-DSCH when inCELL/URA_PCH states.

The WTRU may autonomously transition from the CELL_PCH state to theCELL_FACH state if the WTRU has uplink data or signaling to transmit.Multiple discontinuous reception (DRX) cycle may be defined in theCELL_PCH and URA_PCH states, which is a power saving mechanism thatallows the universal terrestrial radio access network (UTRAN) to quicklyaccess low activity WTRUs.

A WTRU or network that supports enhanced PCH has to also supportenhanced FACH. However, the WTRU or network may support enhanced FACHwithout supporting the enhanced PCH. Therefore, when a WTRU triggers aUTRAN routing area (URA) update and both the WTRU and the networksupport enhanced FACH but not enhanced PCH, a URA UPDATE CONFIRM messagewill be received over the HS-DSCH but the WTRU will receive the pagingmessage over the PCH. However, when the WTRU supports enhanced PCH, boththe URA UPDATE CONFIRM message and paging messages are received over theHS-DSCH.

For paging in the CELL/URA_PCH states, a 3GPP Release 7 WTRU monitors apaging indicator channel (PICH), similar to 3GPP Release 6. Once apaging indication is detected, the WTRU monitors the HS-DSCH forreception of the paging control channel (PCCH) frame rather thanmonitoring the PCH/secondary common control physical channel (S-CCPCH).

When selecting a cell, a Release 7 WTRU determines if the cell supportsenhanced FACH based on the configuration information that is broadcaston the broadcast control channel/broadcast channel (BCCH/BCH). Morespecifically, a system information block (SIB) Type 5/5bis includes twoinformation elements (IEs): “HS-DSCH common system information” and“HS-DSCH paging system information”. These IEs provide configurationinformation necessary for the WTRU to receive HS-DSCH in the CELL_FACH,CELL_PCH and URA_PCH states.

A WTRU determines support for HS-DSCH reception in the CELL/URA_PCHstates based on the configuration information that is broadcast in thecell on the BCCH/BCH. If the HS-DSCH paging system information ispresent in SIB 5/5bis, the WTRU configures itself for reception over theHS-DSCH rather than the PCH/S-CCPCH.

However, a drift radio network controller (DRNC) is not fully aware ofthe WTRU capabilities when in the CELL_PCH state. When the CELL UPDATEmessage is sent to the DRNC, the WTRU only indicates whether it supportsthe enhanced CELL_FACH state. A WTRU with enhanced CELL_FACHcapabilities has an option of supporting HS-DSCH reception only in theCELL_FACH state or HS-DSCH reception both in the CELL_FACH andCELL/URA_PCH states. This is not indicated in the CELL UPDATE messageand thus the DRNC does not know how to page the WTRU. If a serving radionetwork controller (SRNC) attempts to page the WTRU using the pagingtype 1 mechanism, the DRNC does not know which channel the WTRU monitorsfor paging, (i.e., HS-DSCH or PCH/S-CCPCH).

When the WTRU is in the URA_PCH state, the DRNC is unaware of the WTRU'scapabilities unless explicitly indicated by the SRNC. The SRNC might notindicate the WTRU capabilities, (i.e., enhanced CELL_FACH capabilities),to the DRNC if the WTRU in the URA_PCH state is paged by the SRNC andhas roamed to the cell without having performed UTRAN registration orcell update, or if the WTRU is connected to a Release 6 SRNC and roamsto a Release 7 cell in the network.

In the first case, the SRNC sends a PAGING REQUEST message over Iur toan RNC that controls the cells in the UTRAN registration area (URA)group. However, the DRNC is unaware of which paging channel the WTRU ismonitoring, (i.e., HS-DSCH or PCH/S-CCPCH). The DRNC is unaware of theWTRU capabilities unless the WTRU has performed a URA update at anearlier time in one of the cells that are controlled by the RNC. Assuch, the DRNC may page the WTRU over HS-DSCH in all cells that supportpaging over HS-DSCH. However, if the WTRU does not support HS-DSCHreception in the CELL_PCH state, the WTRU will never receive the pagingindication. The DRNC may page the WTRU over PCH/S-CCPCH. However, if theWTRU and the cell both support HS-DSCH reception in the CELL_PCH state,the WTRU will never receive the paging message as it is monitoringHS-DSCH instead of PCH.

In the second case, a Release 7 WTRU roams to a Release 7 cell withinthe same URA, while connected to a Release 6 SRNC. The WTRU will monitorHS-DSCH for paging because the HS-DSCH paging system information isbroadcast in the cell. However, the Release 7 DRNC is unaware of whichchannel the WTRU is monitoring for paging messages since the DRNC doesnot have any knowledge of the WTRU capabilities.

In addition, in the case where the WTRU does not support enhanced PCHbut supports enhanced FACH, if a URA UPDATE is triggered and the CRNC isnot aware of the WTRU capabilities it will not know over what transportchannel to send the RRC messages, (e.g., URA UPDATE CONFIRM message).

SUMMARY

A method and apparatus for paging a WTRU in a CELL_PCH and URA_PCHstates are disclosed. A WTRU may send an indication of an enhanced PCHcapability of receiving an HS-DSCH in CELL_PCH and URA_PCH states, forexample, in a CELL UPDATE message, a URA UPDATE message, or a UTRANMOBILITY INFORMATION CONFIRM message. A DRNC may receive an indicationwhether the WTRU has an enhanced PCH capability from a serving RNC andpage the WTRU based on the indication. An RNC may page the WTRU overboth an HS-DSCH and a PCH/S-CCPCH if a WTRU capability is not known. TheWTRU may monitor both an HS-DSCH and a PCH/S-CCPCH. The WTRU mayconfigure reception over an HS-DSCH based on the capability of the SRNCor configuration from the network.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding of the invention may be had from thefollowing description of a preferred embodiment, given by way of exampleand to be understood in conjunction with the accompanying drawingswherein:

FIG. 1 shows a conventional UTRAN;

FIG. 2 shows a signaling procedure for DRNC-initiated SRNS relocation;and

FIG. 3 shows a signaling procedure for SNRC-initiated SRNS relocation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

When referred to hereafter, the term “WTRU” includes but is not limitedto a user equipment (UE), a mobile station, a fixed or mobile subscriberunit, a pager, a cellular telephone, a personal digital assistant (PDA),a computer, or any other type of user device capable of operating in awireless environment. When referred to hereafter, the term “Node B”includes but is not limited to a base station, a site controller, anaccess point (AP), or any other type of interfacing device capable ofoperating in a wireless environment.

FIG. 1 shows a conventional UTRAN 100. The UTRAN 100 includes aplurality of RNCs 110 a, 110 b and a plurality of Node Bs 120. Each RNC110 a, 110 b has a CRNC function to control one or more Node Bs. An SRNC110 a controls a connection for a WTRU 130. A DRNC 110 b lends resourcesfor the SRNC 110 a for a particular WTRU 130. The WTRU 130 sends a CELLUPDATE message to a CRNC, (the CRNC may be an SRNC or a DRNC), aftercell reselection to support inter RNC cell update and SRNC relocation ina CELL_FACH state. The WTRU 130 sends an URA UPDATE message to a CRNCafter detection of URA change to support inter RNC mobility inCELL/URA_PCH states.

In accordance with a first embodiment, the WTRU may indicate a CRNC theHS-DSCH reception capability in the CELL_PCH state, (hereinafter“enhanced PCH capability), via the CELL UPDATE message. The indicationmay be provided in many different ways. For example, an IE may beincluded in the CELL UPDATE message to indicate that the WTRU supportsHS-DSCH reception in the CELL/URA_PCH states. If this information isprovided, the CRNC may infer that HS-DSCH reception in the CELL_FACHstate is also supported. Optionally, the HS-DSCH reception capability inthe CELL_FACH state may be indicated independently. If this IE is notpresent, the WTRU does not support HS-DSCH reception in the CELL/URA_PCHstates.

Alternatively, the conventional “UE capability indication” may beextended to indicate if the WTRU supports HS-DSCH reception in CELL_FACHand/or CELL/URA_PCH states. The “UE capability indication” may beinterpreted as an enumeration, which may take on the following values:

(1) HS-DSCH in CELL_FACH. If set, the WTRU only supports HS-DSCHreception in the CELL_FACH state;

(2) HS-DSCH in CELL/URA_PCH. If set, the WTRU supports HS-DSCH receptionin the CELL_FACH and in CELL/URA_PCH states; and

(3) None. If set, the WTRU does not support HS-DSCH reception in theCELL_FACH or CELL/URA_PCH states.

When a DRNC receives the CELL UPDATE message indicating that the WTRU isin the CELL_PCH state and supports HS-DSCH reception in the CELL_PCHstate, the DRNC may allocate a dedicated HS-DSCH radio network temporaryidentifier (H-RNTI) and other CELL_PCH specific parameters and transferthese to the SRNC. A CELL UPDATE CONFIRM message is sent over theHS-DSCH to the WTRU.

A DRNC may store the WTRU capability information in a memory. When anSRNC sends a PAGING REQUEST message to the DRNC over Iur, the DRNC maypage the WTRU over an HS-DSCH or a PCH/S-CCPCH based on the capabilityinformation stored in the memory.

If a WTRU supports HS-DSCH reception only in the CELL_FACH state, (i.e.,does not support HS-DSCH reception in the CELL/URA_PCH states), the CRNCdoes not have to allocate a dedicated H-RNTI to the WTRU. However, theCRNC transfers the CELL UPDATE CONFIRM message to the WTRU over theHS-DSCH.

In order to ensure reception of the URA UPDATE CONFIRM message, the DRNCmust be notified of the WTRU's capabilities. The HS-DSCH receptioncapability information may be transmitted in the CELL/URA_PCH statesusing the URA UPDATE message. This allows the DRNC that receives the URAUPDATE message to know if the WTRU supports HS-DSCH reception in theCELL/URA_PCH states.

The indication may be signaled in many different ways. For example, anew IE, (e.g., WTRU capability indication in CELL/URA_PCH), may beincluded in the URA UPDATE message to indicate whether the WTRU supportsHS-DSCH reception in CELL/URA_PCH states. In addition, a new IE, (e.g.,WTRU capability indication in CELL_FACH), may be included in the URAUPDATE message to indicate if the WTRU supports HS-DSCH reception inCELL_FACH.

Alternatively, a new IE, (e.g., WTRU capability indication), that is anenumerated value may be added, where one of the following values can beindicated:

(1) HS-DSCH in CELL_FACH. If this is set, the WTRU only supports HS-DSCHreception in CELL_FACH;

(2) HS-DSCH in CELL/URA_PCH. If this is set, the WTRU supports HS-DSCHreception in CELL_FACH and in CELL/URA_PCH; and

(3) None. No support for HS-DSCH reception in CELL_FACH and/orCELL/URA_PCH.

A new IE may be added to indicate that the WTRU supports 3GPP release 7.

When a WTRU roams between cells that do not support enhanced CELL_FACHand/or enhanced PCH, (e.g., Release 6 cells), and cells that supportenhanced CELL_FACH and/or enhanced PCH, (e.g., Release 7 cells), theWTRU capability information may be transferred to an RNC. The WTRUcapability information may be transferred by triggering a cell updateprocedure or a URA update procedure, where the WTRU may include thecapability information as described above.

In a URA_PCH state, a WTRU may perform a cell update or URA updateprocedure even when roaming within the same URA if the capabilities of anew cell are different than the capabilities of an old cell. Preferably,the indication of the WTRU capabilities by transferring the URA UPDATEmessage is performed if the new cell supporting enhanced FACH and/orenhanced PCH is controlled by a CRNC that is different than the SRNC,(i.e., an Iur is established between the SRNC and the CRNC).

The WTRU may determine that the CRNC is different than the SRNC if anSRNC identify in the UTRAN radio network temporary identity (U-RNTI) ofthe WTRU is different than the 12 most significant bits of the cellidentity that is broadcast throughout the cell. This added restrictionon the transfer of URA UPDATE message reduces the number of unnecessaryURA UPDATE messages that need to be sent to the UTRAN.

In order to further reduce the transfer of unnecessary URA UPDATEmessages including WTRU capability information, the triggering criterionmay be restricted to the following situations:

(1) A WTRU has roamed from a cell that does not support enhanced FACHand/or enhanced PCH to a cell that supports enhanced FACH and/orenhanced PCH;

(2) The new cell is controlled by a CRNC that is different than theSRNC;

(3) The new cell is controlled by a CRNC that is different from the CRNCthat controlled the previous cell; or

(4) The WTRU is unaware if the SRNC to which it is connected supportsenhanced FACH and/or enhanced PCH.

The WTRU may determine if the SRNC to which it is connected supportsenhanced PCH by maintaining an internal variable indicating SRNCenhanced FACH and/or PCH capability. When the internal variable is setto FALSE, the WTRU behaves as if it is unaware if the SRNC to which itis connected supports enhanced FACH and/or enhanced PCH. When theinternal variable is set to TRUE, the WTRU knows that the SRNC supportsenhanced FACH and/or enhanced PCH.

The internal variable is initialized to FALSE and reset to FALSE when atleast one of the following conditions is satisfied:

(1) A new U-RNTI is assigned to the WTRU;

(2) The WTRU RRC state changes from CELL_DCH to URA_PCH;

(3) The WTRU RRC state changes from CELL_FACH to URA_PCH;

(4) The WTRU RRC state changes from CELL_PCH to URA_PCH;

(5) The WTRU RRC state changes from URA_PCH to CELL_PCH or CELL_FACH orCELL_DCH;

(6) The WTRU receives a URA UPDATE CONFIRM message or any other RRCmessage in a cell that does not support enhanced PCH and/or enhancedFACH and a new U-RNTI is assigned; and

(7) The WTRU receives any RRC message while in CELL_DCH state and a newU-RNTI is assigned.

The internal variable is set to TRUE when at least one of the followingconditions is satisfied:

(1) If the WTRU successfully receives a URA UPDATE CONFIRM message afterhaving triggered the transfer of a URA UPDATE message includingcapability information according to the triggering condition above;

(2) If the WTRU successfully receives a URA UPDATE CONFIRM message afterhaving transferred a URA UPDATE message in a cell that supports enhancedFACH and/or enhanced PCH;

(3) If the WTRU successfully receives a CELL UPDATE CONFIRM messageafter having transferred a CELL UPDATE message in a cell that supportsenhanced FACH and/or enhanced PCH;

(4) If the WTRU roams to a cell that supports enhanced FACH and/orenhanced PCH and the cell is controlled by the SRNC to which it isconnected, (i.e., the CRNC and the SRNC are the same node); and

(5) The WTRU initiates an RRC connection in a cell that supportsenhanced FACH and/or enhanced PCH.

Alternatively, in order to reduce the number unnecessary transfers ofURA UPDATE message, the SRNC may initiate a serving radio networksubsystem (SRNS) relocation procedure when it receives a URA UPDATEmessage indicating enhanced FACH and/or enhanced PCH from a WTRU havingroamed to a cell that is controlled by a different RNC. This isexplained in detail with reference to FIG. 3 below. Preferably, the SRNCmay initiate the SRNS relocation when it receives a URA UPDATE messagethat was triggered by any of the conditions above. The SRNC maydetermine if the URA UPDATE message was triggered according to one ofthose conditions if the WTRU has not changed URA and the URA UPDATEmessage has been received prior to expiry of a periodic timer fortransfer of the URA UPDATE message.

Alternatively, the SRNC may include in the Downlink Signaling TransferRequest radio network subsystem application part (RNSAP) message a newIE indicating that the WTRU supports enhanced FACH and/or enhanced PCH,and/or a new IE indicating which channel the DRNC should use to transferthe URA UPDATE CONIFRM message or any other message that is included inthe Downlink Signaling Transfer Request.

As an alternative, the WTRU may include its capabilities information aspart of the UTRAN MOBILITY INFORMATION CONFIRM message that is sent backto an SRNC after reception of a CELL UPDATE CONFIRM, URA UPDATE CONFIRMor UTRAN MOBILITY INFORMATION messages from the SRNC. Alternatively, thetrigger for sending the UTRAN MOBILITY INFORMATION CONFIRM message maybe an indication that SRNS relocation has taken place. A WTRU maydetermine that SRNS relocation has taken place if a new U-RNTI isassigned in the URA/CELL UPDATE CONFIRM message, or any other RRC layermessages.

In accordance with a second embodiment, the SRNC may explicitly indicateto a DRNC how to page the WTRU in the PAGING REQUEST message. Based onthe WTRU radio access capabilities indicated during the RRC connectionestablishment or any subsequent capability indication, the SRNC mayindicate to the DRNC(s) if the WTRU supports enhanced PCH in the RNSAPPAGING REQUEST message over lur.

A new IE, (e.g., enhanced PCH indicator), may be added in the PAGINGREQUEST message. The DRNC pages the WTRU over the HS-DSCH if the cell(s)within the URA support enhanced PCH, and the “enhanced PCH indicator” IEin the PAGING REQUEST message indicates that the WTRU supports enhancedPCH. Otherwise, the DRNC pages the WTRU over the PCH/S-CCPCH. If not allcells within the URA support enhanced PCH, the DRNC may page the WTRUover the HS-DSCH for the cells that support the enhanced PCH and overthe PCH/S-CCPCH for the cells that do not have enhanced PCHcapabilities.

The enhanced PCH indicator may take one or a combination of thefollowing forms:

(1) An optional IE, which is present only if enhanced PCH is supported;optionally, the lack of this IE may imply that the SRNC is not a Release7 SRNC;

(2) An IE that may be set to TRUE or FALSE;

(3) An IE that is an enumerated value, where the following values areindicated:

-   -   i. Enhanced PCH. The SRNC supports enhanced PCH;    -   ii. Optionally, an enumerated value for enhanced FACH may also        be included; and    -   iii. No HS-DSCH support. The SRNC does not support enhanced PCH        (or optionally enhanced FACH);

(4) An IE that is provided independently of the paging area choice;

(5) An IE that is provided only if the paging area choice is URA; and

(6) An IE that indicates that the WTRU to be paged is 3GPP release 7compliant.

Alternatively, a new radio network system application part (RNSAP)message may be defined to support paging over the HS-DSCH, (e.g., anHS-DSCH PAGING REQUEST message). The SRNC may use the HS-DSCH PAGINGREQUEST message to page the WTRU over the HS-DSCH, and the conventionalPAGING REQUEST message to page the WTRU over the PCH/S-CCPCH.

If an SRNC does not support the enhanced CELL_FACH state, (i.e., Release6 or older RNC), the SRNC does not include the “enhanced PCH indicator”IE in the PAGING REQUEST message. If the DRNC is unaware of the SRNCcapabilities, the DRNC may take this as an indication that the WTRU doesnot support paging over HS-DSCH and page the WTRU over a PCH/S-CCPCH.However, if the cell to which the WTRU has roamed supports paging overan HS-DSCH, the WTRU will be monitoring the HS-DSCH after detection of apaging indication on a PICH.

Alternatively, if the “enhanced PCH indicator” IE is not present in thePAGING REQUEST message, the DRNC may interpret that the SRNC does notsupport enhanced CELL_FACH, (i.e., Release 6 or older RNC). The“enhanced PCH indicator” IE may be mandatory for a Release 7 RNSAPPAGING REQUEST message.

However, relying on the presence of this IE does not indicate to theDRNC how to page the WTRU. For example, the Release 7 WTRU might beconnected to a Release 6 SRNC while monitoring an HS-DSCH in the Release7 cell. Therefore, when the “enhanced PCH indicator” IE is not present,the DRNC may page the WTRU over both PCH/S-CCPCH and HS-DSCH to ensurethat the WTRU receive the paging message, may page the WTRU over thePCH/S-CCPCH, and/or may rely on previous embodiments to know how to pagethe WTRU, (i.e., WTRU capabilities).

In accordance with a third embodiment, the DRNC may send a pagingmessage over an HS-DSCH and a PCH/S-CCPCH when the DRNC is unaware ofthe WTRU capabilities. The DRNC may determine the WTRU capabilitiesaccording to any of the mechanisms set forth above.

In accordance with a fourth embodiment, a WTRU in the URA_PCH orCELL_PCH states may monitor both the HS-DSCH and the PCH/S-CCPCH for thePCCH frame after decoding a paging indication over the PICH if the cellsupports paging over HS-DSCH, (i.e., Release 7 cell), if the WTRUsupports paging over HS-DSCH, (i.e., Release 7 WTRU), and one or more ofthe following conditions are satisfied: (1) The WTRU has roamed from acell that does not support enhanced CELL_FACH to a cell that supportsenhanced CELL_FACH or (2) the WTRU is unaware of the capabilities of theSRNC to which it is connected, (i.e., the WTRU does not know if the SRNCsupports enhanced CELL_FACH state). The WTRU may determine the SRNCcapabilities according to the methods set forth below.

Alternatively, the WTRU may always monitor both HS-DSCH and PCH/S-CCPCHfor reception of the PCCH frame.

Methods for determining SRNC capabilities are disclosed hereafter. Whena WTRU is in an IDLE mode, (i.e., the WTRU does not have an RRCconnection to the UTRAN), the WTRU may implicitly determine that the RNCto which it is attempting to connect supports enhanced CELL_FACH if thecell supports enhanced CELL_FACH, which is determined based on theHS-DSCH common channel information broadcast in SIB 5/5bis.

If the WTRU has an RRC connection with an SRNC, (i.e., the WTRU is in aCONNECTED mode), the following methods may be used, individually or inany combination, to determine if the SRNC supports enhanced CELL_FACH.

If the WTRU has configured itself for reception of HS-DSCH in CELL_FACHstate at any point throughout the life of its RRC connection with theSRNC, the WTRU may determine that the SRNC supports enhanced CELL_FACHstate. Alternatively, if the WTRU has been configured to operate usingany 3GPP Release 7 feature, (such as multiple-input multiple-output(MIMO) and 64 quadrature amplitude modulation (QAM) HSDPA), whileconnected to the SRNC, then the WTRU may determine that the SRNCsupports enhanced CELL_FACH state. Preferably, a Release 7 SRNC mayindicate to the WTRU that an SRNS relocation will or has taken place inorder to ensure that the WTRU knows the capabilities of the SRNC towhich it is connected.

Alternatively, new dedicated RRC-layer signaling between the UTRAN andthe WTRU may be introduced to indicate to the WTRU that its SRNCsupports enhanced CELL_FACH state and/or to configure the WTRU tooperate in enhance PCH. The capability or configuration information maybe added to conventional RRC messages, (e.g., RRC CONNECTION SETUP, CELLUPDATE CONFIRM, URA UPDATE CONFIRM messages), or transferred in a newRRC message that is used to indicate the capabilities of the SRNC,(e.g., SRNS CAPABILITY INFORMATION or ENHANCED PCH SETUP messages). Thecapability information may indicate support for enhanced CELL_FACHstate, support for 3GPP Release 7 or beyond, support for enhanced PCH,and/or support for paging over HS-DSCH.

Alternatively, new broadcast signaling that provides a list of RNCs inthe UTRAN that support enhanced CELL_FACH and/or 3GPP Release 7 orbeyond maybe provided.

Preferably, the SRNC capability information is considered as valid bythe WTRU throughout the life of its RRC connection with the SRNC. Asource SRNC or a target SRNC may indicate capabilities update to theWTRU if SRNS relocation takes place to the target SRNC having differentcapabilities than the source SRNC. Alternatively, the Release 7 sourceand/or target SRNC may notify the WTRU that SRNS relocation is about toor has taken place. Preferably, a mechanism of exchange of capabilitybetween RNCs over Iur may be available. For example, during SRNSrelocation, a source SRNC may indicate to a target SRNC the enhanced PCHor Release 7. The lack of capability indication may be interpreted suchthat the peer RNC does not support this capability.

In accordance with another embodiment, a WTRU may act as indicated by anSRNS. The SRNS may explicitly indicate to the WTRU whether it shouldsupport enhanced PCH or Release 7. The SRNS may configure the WTRU tooperate using enhanced PCH. The WTRU's behavior may be modified tomonitor the S-CCPCH when the SRNS does not support enhanced PCH or theSRNC does not configure the WTRU to operate in enhanced PCH mode. Thisapplies even if the DRNC supports enhanced PCH, and the cell the WTRU ismonitoring is broadcasting HS-DSCH paging system information inSIB5/5bis. The WTRU's behavior may also be modified to monitor theS-CCPCH when the SRNS supports enhanced PCH but the HS-DSCH pagingsystem information is not broadcasted in SIB5/5bis.

Alternatively, the WTRU may monitor the HS-DSCH when the SRNS indicatesthat it should support HS-DSCH or Release 7. The WTRU may also monitorthe HS-DSCH when the SRNS explicitly configures the WTRU to monitor theHS-DSCH. HS-DSCH system information is broadcast in SIB5/5bis.

The SRNS capabilities or configuration information may be indicated tothe WTRU using one or more of the following methods:

(1) Addition of a new IE, (e.g., enhanced PCH support), that indicatesthe SRNS capability in the RRC messages that are used to move the WTRUto CELL_PCH and/or URA_PCH;

(2) Addition of a new IE, (e.g., enhanced PCH support), that indicatesthe SRNC capability in other RRC messages such as URA UPDATE CONFIRM,CELL UPDATE CONFIRM, UTRAN MOBILITY INFORMATION messages; and

(3) Introduction of a new message, (e.g., “SRNS RELOCATION INFO”), thatis signaled to the WTRU when SRNS relocation occurs. The SRNCcapabilities are indicated within this message.

The new IE, (e.g., enhanced PCH support), may take one or a combinationof the following forms:

(1) An IE that may be set to TRUE or FALSE;

(2) An IE that is an enumerated value where the following value isindicated:

-   -   i. Enhanced PCH. The SRNC supports enhanced PCH; and    -   ii. Optionally, an enumerated value for enhanced FACH may also        be included;

(3) An IE that is an enumerated value where the following value isindicated:

-   -   i. Enhanced PCH. The SRNC supports enhanced PCH;    -   ii. Optionally, an enumerated value for enhanced FACH may also        be included; and    -   iii. No HS-DSCH support. The SRNC does not support enhanced PCH        (or optionally enhanced FACH).

(4) An optional IE, which is present only if enhanced PCH is supportedby the SRNC; and

(5) An optional IE, which is present only if enhanced FACH is supportedby the SRNC.

Preferably, the lack of this IE implies that the SRNC is a Release 6 orolder SRNC and thus the WTRU implicitly knows that the SRNC does notsupport enhanced PCH and/or Release 7. This IE may be mandatory for allRRC messages mentioned above or it may be mandatory if the RRC messageis indicating a change of U-RNTI, (e.g., IE “New U-RNTI” is present).The presence of the new U-RNTI may imply that there has been SRNSrelocation.

On the UTRAN side, the DRNC preferably pages over PCH/S-CCPCH when theSRNC is not a Release 7 SRNC or if the DRNC does not support enhancedPCH. Otherwise the DRNC pages over an HS-DSCH if the cell in which it ispaging supports enhanced PCH. Signaling of the SRNC capabilities to theDRNC may be performed using one of the methods described above.

Preferably, the WTRU configuration is maintained valid, (i.e., receptionof paging over HS-DSCH rather than S-CCPCH), throughout the life of theconnection to the SRNC. The WTRU may reevaluate support for enhanced PCHor may be reconfigured by the UTRAN to support enhanced PCH wheneverSRNS relocation takes place.

The WTRU may recognize a change of SRNC or SRNS relocation by detectinga change of the U-RNTI in any RRC message. Optionally, the WTRU mayrecognize that a change of SRNC has taken place if the bits related toS-RNC ID within the U-RNTI have changed. If such a condition occurs andthe enhanced PCH support IE is not present in the message that was usedto change the U-RNTI, the WTRU may not operate in enhanced PCH when inCELL/URA_PCH states, and may instead monitor the S-CCPCH. Alternatively,if the enhanced PCH support IE is present in the message that was usedto change the U-RNTI, the WTRU may start or, if started, continueenhanced PCH operation.

The UTRAN, (either a source SRNC or a target SRNC), may indicate acapabilities update to the WTRU if SRNS relocation takes place to thetarget SRNC having different capabilities than the source SRNC.Alternatively, the Release 7 source SRNC and target SRNC may notify theWTRU that SRNS relocation is about to or has taken place.

Preferably, a mechanism for exchanging capability information betweenRNCs over Iur is available. For example, during SRNS relocation, thesource SRNC may indicate to the target SRNC the enhanced PCH and/orRelease 7. A lack of capability indication may be interpreted to meanthat the peer RNC does not support this capability.

In accordance with another embodiment, a WTRU may determine whether itshould monitor the PCH/S-CCPCH or the HS-DSCH based on capabilities ofthe WTRU and the cell and an additional condition related to thereception method that the WTRU used during a previous communication withthe network in the current RRC connection. This additional conditionensures that the network and the WTRU are in sync with respect to thetransport channel used for CELL/URA_PCH states.

The WTRU may monitor only the HS-DSCH in CELL/URA_PCH states if the WTRUhas sent RRC messages, since the beginning of the RRC connection, withRelease 7 SRNC and DRNC that support the enhanced PCH capability. Fromthe time when the WTRU successfully sends an RRC message to an RNC thatdoes not support the capability, the WTRU monitors only the S-CCPCH. TheWTRU ensures that the network only sends paging over the S-CCPCH by notincluding the capability IE in all subsequent RRC messages until the endof the RRC connection. Detailed procedures implemented in the WTRU andthe network are described below.

Upon successful RRC connection, a WTRU that is capable of receivingHS-DSCH in CELL/URA_PCH states sets an internal variable, (e.g.,HS_DSCH_RECEPTION_CELL_PCH), that indicates whether the WTRU may attemptto receive HS-DSCH in CELL/URA_PCH states. The variable is set to TRUEif the cell supports the capability, and FALSE if it does not supportit.

Upon cell reselection, the WTRU starts receiving HS-DSCH in CELL/URA_PCHstates only if the cell supports this capability, as indicated by thebroadcast SIB, and if the variable HS_DSCH_RECEPTION_CELL_PCH is set toTRUE. The WTRU sets the variable HS_DSCH_RECEPTION_CELL_PCH to FALSEupon completion of a successful cell update or URA update procedurewithin a cell that does not support the capability. The internalvariable keeps this value until release of the RRC connection or untilthe next successful RRC connection request. When the internal variableis set to FALSE, the WTRU does not include its capability IE in the CELLUPDATE or URA UPDATE message, and it does not receive on HS-DSCH inCELL/URA_PCH states, (i.e., it receives on S-CCPCH). Optionally, theWTRU may set the internal variable to TRUE if the WTRU determines thatSRNS relocation has taken place, (for instance, based on a change of acertain part of the U-RNTI), and if the cell supports enhanced PCH.

When paging information or data is transmitted to a WTRU in Cell_PCH orURA_PCH states, the SRNC, (if Release 7), sends the WTRU capabilityinformation along with the paging request to the DRNC if the SRNCdetermines that the WTRU supports the enhanced PCH capability, asdescribed above. If the DRNC is Release 7 and supports the capability,the DRNC sends the paging message over an HS-DSCH in the concerned cellsthat supports the capability, and over an S-CCPCH in the other concernedcells. In all other cases, the paging message is sent over an S-CCPCHover all concerned cells. The concerned cells include all cellscontrolled by the DRNC and part of the URA if the WTRU is in the URA_PCHstate, or a single cell if the WTRU is in the CELL_PCH state.

A DRNC that does not support this capability, (e.g., a Release 6 DRNC),sends the paging message over an S-CCPCH. In addition, an SRNC that doesnot support the capability will not send the capability of the WTRUalong with the paging request to the DRNC.

If the SRNC is the same as the CRNC, (i.e., if there is no DRNC), andthe SRNC determines that the WTRU supports the enhanced PCH capability,the SRNC sends the paging message over an HS-DSCH in all concerned cellsthat support the enhanced PCH capability, and over an S-CCPCH in theother concerned cells. Only a Release 7 SRNC may determine that the WTRUsupports the enhanced PCH capability. A Release 6 SRNC sends the pagingmessage over an S-CCPCH in all concerned cells.

A Release 7 SRNC determines the enhanced PCH capability of the WTRUbased on whether the capability IE is contained in received messagessuch as CELL UPDATE, URA UPDATE, or RRC CONNECTION REQUEST messagestransmitted directly from the WTRU if the SRNC is the CRNC of the cellfrom which the WTRU transmits the message, or relayed from the CRNC ofthe cell from which the WTRU transmits the message. In the latter case,the capability is only relayed to the SRNC if the CRNC is a Release 7CRNC. If the CRNC is a Release 6 CRNC, the capability is not relayed tothe SRNC and the SRNC determines that the WTRU is not capable ofreceiving HS-DSCH in CELL_PCH or URA_PCH states.

A Release 7 SRNC does not take into consideration the presence of acapability IE in past messages when determining the capability of theWTRU upon reception of a new message transmitted from this WTRU orrelayed from the CRNC. For instance, the SRNC has determined at acertain point that the WTRU has the enhanced PCH capability andsubsequently receives a message from the WTRU or a message relayed fromthe CRNC that does not indicate the enhanced PCH capability, the SRNCdetermines from that point that the WTRU does not have the enhanced PCHcapability.

Alternatively, the WTRU may only modify the internal variable(HS_DSCH_RECEPTION_CELL_PCH) to FALSE if the WTRU receives informationfrom the network indicating that the SRNC does not support the enhancedPCH. Such information may be an RRC message from the network containingan IE “new U-RNTI” in a cell where the enhanced PCH feature is notavailable. The information may be an RRC message from the networkcontaining the IE “new U-RNTI” and the new U-RNTI value indicates thatthe RNC ID has changed (SRNS relocation) in a cell where the enhancedPCH feature is not available. The information may be a UTRAN mobilityinformation message in a cell where the enhanced PCH feature is notavailable. An RNC may obtain the WTRU capability information through theRRC connection establishment procedure or through the SRNS relocationprocedure. It is not required that the RNC obtains the capabilityinformation through CELL UPDATE or URA UPDATE messages. Detailedprocedures in the WTRU and the network are described below.

Upon successful RRC connection, a WTRU that is capable of receivingHS-DSCH in Cell/URA_PCH states may set an internal variable, (e.g.,HS_DSCH_RECEPTION_CELL_PCH), that indicates whether the WTRU may attemptto receive HS-DSCH in Cell/URA_PCH states. The internal variable is setto TRUE if the cell supports the capability, and FALSE if it does notsupport it.

Upon cell reselection, the WTRU may start receiving HS-DSCH inCell/URA_PCH states only if the cell supports this capability, asindicated by the broadcast SIB, and if the internal variableHS_DSCH_RECEPTION_CELL_PCH is set to TRUE. The WTRU sets the variableHS_DSCH_RECEPTION_CELL_PCH to FALSE upon reception of an RRC messagesatisfying one or more of the conditions above. The variable keeps thisvalue until release of the RRC connection or until the next successfulRRC connection request.

When paging or data is transmitted to a WTRU in Cell_PCH or URA_PCHstates, the SRNC (if Release 7) sends the WTRU capability informationalong with the paging request to the DRNC if the SRNC determines thatthe WTRU supports the capability and will attempt reception of paging onHS-DSCH.

The SRNC obtains the WTRU capability information by an RRC connectionestablishment procedure if the WTRU started its RRC connection with thisRNC, or by SRNS relocation through transfer of WTRU capabilityinformation within a transparent container from the source SRNC to thetarget SRNC. It should be noted that such transfer is only possible ifthe source SRNC knows about the enhanced PCH capability (Release 7 andbeyond).

The SRNC knows that the WTRU will attempt reception of paging on anHS-DSCH if it knows the WTRU supports the capability and if it has neversent an RRC message to the WTRU that satisfies the same condition or setof conditions that the WTRU checks for setting its variable to FALSE.The UTRAN and WTRU must use the same condition or set of conditions.This is preferably pre-determined.

If the DRNC is Release 7 DRNC that supports the enhanced PCH capabilityand receives a paging request message from the SRNC indicating that theWTRU supports the enhanced PCH capability, the DRNC sends the pagingmessage over an HS-DSCH in the concerned cells that support the enhancedPCH capability, and over an S-CCPCH in the other concerned cells. In allother cases the paging message is sent over the S-CCPCH over allconcerned cells. The concerned cells include all cells controlled by theDRNC and part of the URA if the WTRU is in the URA_PCH state, or asingle cell if the WTRU is in the Cell_PCH state. A DRNC that does notsupport the enhanced PCH capability sends the paging message over anS-CCPCH. An SRNC that does not support the enhanced PCH capability doesnot send the WTRU capability information along with the paging requestto the DRNC.

If the SRNC is the same as the CRNC, (i.e., there is no DRNC), and theSRNC determines that the WTRU supports the enhanced PCH capability, theSRNC sends the paging message over an HS-DSCH in all concerned cellsthat supports the capability, and over an S-CCPCH in the other concernedcells. Only a Release 7 SRNC may determine that the WTRU has theenhanced PCH capability. A Release 6 SRNC sends the paging message overan S-CCPCH in all concerned cells.

FIG. 2 shows a signaling procedure 200 for DRNC-initiated SRNSrelocation. A Release 7 DRNC initiates an SRNS relocation procedure whenit realizes that a Release 7 WTRU has roamed from a Release 7 cell whilehaving an RRC connection to a Release 6 SRNC. A WTRU performs cellreselection from a Release 6 cell to a Release 7 cell (step 202). TheWTRU then sends a URA UPDATE message to a target RNC, (i.e., DRNC) via arandom access channel (RACH) (step 204). The URA UPDATE message includesan indication of the WTRU enhanced PCH capability as stated above. Thetarget RNC recognizes the capability mismatch in WTRU and a source RNC,(i.e., SRNC) (step 206). The target RNC sends a relocation requestmessage to the core network over the Iu interface to initiate the SRNSrelocation procedure (step 208). The relocation request may be realizedby either extending the use of conventional RANAP signaling, (e.g.,RELOCATION REQUIRED), to allow the target RNC to request SRNS relocationor by defining a new RANAP signal, (e.g., RELOCATION REQUEST), betweenthe target RNC and the CN.

The core network, the source RNC and the target RNC perform SRNSrelocation (step 210). Once the SRNS relocation is complete, the newSRNC, which was previously the DRNC, creates and transfers a Release 7URA UPDATE CONFIRM message to the WTRU over the HS-DSCH (step 212).

Alternatively, the DRNC transfers a relocation request message over theIur interface (RNSAP) and the SRNC may initiate the conventional SRNSrelocation procedure with the core network over the Iu interface.

FIG. 3 shows a signaling procedure 300 for SRNC-initiated SRNSrelocation. A WTRU performs cell reselection from a Release 6 cell to aRelease 7 cell (step 302). The WTRU then sends a URA UPDATE message to atarget RNC, (i.e., DRNC) via a random access channel (RACH) (step 304).The URA UPDATE message includes an indication of the WTRU enhanced PCHcapability as stated above. The target RNC sends an Uplink SignalingTransfer message to a source RNC, (i.e., SRNC) (step 306). The SRNCrecognized capabilities mismatch in the WTRU and the SRNC and initiatesSRNS relocation procedure (step 308).

The SRNC initiates an SRNS relocation procedure if one or a combinationof the following conditions is satisfied:

(1) The SRNC receives an RRC message from a WTRU indicating that theWTRU has capabilities that the SRNC does not support, (e.g., WTRU isRelease 7 WTRU and the SRNC is Release 6 SRNC);

(2) The SRNC receives an Uplink Signaling Transfer message over Iurcontaining a dedicated H-RNTI when the SRNC does not support enhancedPCH;

(3) The WTRU has roamed to a cell that is controlled by an RNC, (i.e.,DRNC), that has capabilities that are not supported by the SRNC; or

(4) The SRNC that does not support enhanced PCH receives a URA UPDATEmessage from a WTRU indicating that it supports enhanced PCH, when theWTRU roams to a cell that is controlled by a different RNC.

The core network, the source RNC and the target RNC perform SRNSrelocation (step 310). Once the SRNS relocation is complete, the newSRNC, which was previously the DRNC, creates and transfers a Release 7URA UPDATE CONFIRM message to the WTRU over the HS-DSCH (step 312).Preferably, the target RNC of the relocation procedure would be theexisting DRNC, (i.e., the CRNC that controls the cell to which the WTRUis connected).

Two or more RNCs in a UTRAN may exchange information related tocapability of the WTRUs. A new RNSAP message may be used to allow oneRNC with knowledge of WTRU capability to share the information withanother RNC. The RNC may send the WTRU capability information to anygiven RNC. The RNC may broadcast the WTRU capability information to manyRNCs. Alternatively, one RNC may request another RNC to send WTRUcapability information if it has knowledge regarding capabilities agiven WTRU.

Although the features and elements of the present invention aredescribed in the preferred embodiments in particular combinations, eachfeature or element can be used alone without the other features andelements of the preferred embodiments or in various combinations with orwithout other features and elements of the present invention. Themethods or flow charts provided in the present invention may beimplemented in a computer program, software, or firmware tangiblyembodied in a computer-readable storage medium for execution by ageneral purpose computer or a processor. Examples of computer-readablestorage mediums include a read only memory (ROM), a random access memory(RAM), a register, cache memory, semiconductor memory devices, magneticmedia such as internal hard disks and removable disks, magneto-opticalmedia, and optical media such as CD-ROM disks, and digital versatiledisks (DVDs).

Suitable processors include, by way of example, a general purposeprocessor, a special purpose processor, a conventional processor, adigital signal processor (DSP), a plurality of microprocessors, one ormore microprocessors in association with a DSP core, a controller, amicrocontroller, Application Specific Integrated Circuits (ASICs), FieldProgrammable Gate Arrays (FPGAs) circuits, any other type of integratedcircuit (IC), and/or a state machine.

A processor in association with software may be used to implement aradio frequency transceiver for use in a wireless transmit receive unit(WTRU), user equipment (UE), terminal, base station, radio networkcontroller (RNC), or any host computer. The WTRU may be used inconjunction with modules, implemented in hardware and/or software, suchas a camera, a video camera module, a videophone, a speakerphone, avibration device, a speaker, a microphone, a television transceiver, ahands free headset, a keyboard, a Bluetooth® module, a frequencymodulated (FM) radio unit, a liquid crystal display (LCD) display unit,an organic light-emitting diode (OLED) display unit, a digital musicplayer, a media player, a video game player module, an Internet browser,and/or any wireless local area network (WLAN) module.

1. A method for paging a wireless transmit/receive unit (WTRU) in aCELL_PCH and URA_PCH states, the method comprising: a WTRU sending anindication indicating an enhanced paging channel (PCH) capability ofreceiving a high speed downlink shared channel (HS-DSCH) in CELL_PCH andURA_PCH states.
 2. The method of claim 1 further comprising: the WTRUsending a second indication indicating an enhanced forward accesschannel (FACH) capability of receiving the HS-DSCH in a CELL_FACH state.3. The method of claim 1 wherein the indication is included in one of aCELL UPDATE message, a URA UPDATE message, and a UTRAN MOBILITYINFORMATION CONFIRM message.
 4. The method of claim 3 wherein the CELLUPDATE message and the URA UPDATE message including the indication aresent if capabilities of a new cell are different than capabilities of anold cell.
 5. The method of claim 3 wherein the URA UPDATE messageincluding the indication is sent if a new cell supporting enhanced PCHis controlled by a controlling radio network controller (CRNC) that isdifferent than a serving radio network controller (SRNC).
 6. The methodof claim 5 wherein the WTRU determines that the CRNC is different thanthe SRNC if an SRNC identity in a UTRAN radio network temporary identity(U-RNTI) is different than 12 most significant bits of a cell identity.7. The method of claim 3 wherein the WTRU sends the URA UPDATE messageincluding the indication if a WTRU has roamed from a cell that does notsupport enhanced FACH and/or enhanced PCH to a cell that supportsenhanced FACH and/or enhanced PCH.
 8. The method of claim 3 wherein theWTRU sends the URA UPDATE message including the indication if a new cellis controlled by a controlling radio network controller (CRNC) that isdifferent from a CRNC that controlled a previous cell.
 9. The method ofclaim 1 wherein the WTRU determines if a serving radio networkcontroller (SRNC) to which the WTRU is connected supports enhanced PCHby maintaining an internal variable indicating SRNC enhanced FACH and/orPCH capability.
 10. The method of claim 9 wherein the internal variableis set to FALSE if any one of following conditions is satisfied: if anew UTRAN radio network temporary identity (U-RNTI) is assigned to theWTRU, if a WTRU radio network controller (RRC) state changes fromCELL_DCH to URA_PCH, if a WTRU RRC state changes from CELL_FACH toURA_PCH, if a WTRU RRC state changes from CELL_PCH to URA_PCH, if a WTRURRC state changes from URA_PCH to CELL_PCH or CELL_FACH or CELL_DCH, ifthe WTRU receives an RRC message in a cell that does not supportenhanced PCH and/or enhanced FACH and a new U-RNTI is assigned, and ifthe WTRU receives an RRC message while in CELL_DCH state and a newU-RNTI is assigned.
 11. The method of claim 9 wherein the internalvariable is set to TRUE when at least one of following conditions issatisfied: if the WTRU successfully receives a URA UPDATE CONFIRMmessage after having triggered a transfer of a URA UPDATE messageincluding the indication, if the WTRU successfully receives a URA UPDATECONFIRM message after having transferred a URA UPDATE message in a cellthat supports enhanced FACH and/or enhanced PCH, if the WTRUsuccessfully receives a CELL UPDATE CONFIRM message after havingtransferred a CELL UPDATE message in a cell that supports enhanced FACHand/or enhanced PCH, if the WTRU roams to a cell that supports enhancedFACH and/or enhanced PCH and the cell is controlled by a serving radionetwork controller (SRNC) to which the WTRU is connected, and if theWTRU initiates an RRC connection in a cell that supports enhanced FACHand/or enhanced PCH.
 12. A method for paging a wireless transmit/receiveunit (WTRU) in a CELL_PCH and URA_PCH states, the method comprising:receiving an indication indicating whether the WTRU has an enhancedpaging channel (PCH) capability of receiving a high speed downlinkshared channel (HS-DSCH) in CELL_PCH and URA_PCH states; and paging theWTRU based on the indication.
 13. The method of claim 12 wherein theindication is included in a PAGING REQUEST message from a serving radionetwork controller (SRNC).
 14. The method of claim 13 wherein theindication is present in the PAGING REQUEST message only if the WTRU hasan enhanced PCH capability.
 15. The method of claim 13 wherein theindication is presented in the PAGAGIN REQUEST message only if the SRNChas an enhanced PCH capability.
 16. The method of claim 13 wherein theindication is provided independently of a paging area choice.
 17. Themethod of claim 13 wherein the indication is provided only if a pagingarea choice is UTRAN routing area (URA).
 18. The method of claim 13wherein if the indication is not present in the PAGING REQUEST message,the WTRU is paged over a PCH/secondary common control physical channel(S-CCPCH).
 19. The method of claim 13 wherein if the indication is notpresent in the PAGING REQUEST message, the WTRU is paged over both anHS-DSCH and a PCH/secondary common control physical channel (S-CCPCH).20. A method for paging a wireless transmit/receive unit (WTRU) in aCELL_PCH and URA_PCH states, the method comprising: receiving a PAGINGREQUEST message for the WTRU; and paging the WTRU over both a high speeddownlink shared channel (HS-DSCH) and a paging channel (PCH)/secondarycommon control physical channel (S-CCPCH) if a capability of the WTRU ofreceiving an HS-DSCH in CELL_PCH and URA_PCH states is not known.
 21. Amethod for paging a wireless transmit/receive unit (WTRU) in a CELL_PCHand URA_PCH states, the method comprising: decoding a paging indicationover a paging indicator channel (PICH); monitoring both a high speeddownlink shared channel (HS-DSCH) and a paging channel (PCH)/secondarycommon control physical channel (S-CCPCH) in one of CELL_PCH and URA_PCHstates; and receiving a paging message.
 22. The method of claim 21wherein the WTRU monitors both the HS-DSCH and the PCH/S-CCPCH if aserving cell supports paging over HS-DSCH.
 23. The method of claim 22wherein the WTRU monitors both the HS-DSCH and the PCH/S-CCPCH if theWTRU has roamed from a cell that does not support enhanced CELL_FACH toa cell that supports enhanced CELL_FACH.
 24. The method of claim 22wherein the WTRU monitors both the HS-DSCH and the PCH/S-CCPCH if theWTRU is unaware of capabilities of a serving radio network controller(SRNC) to which the WTRU is connected.
 25. A method for paging awireless transmit/receive unit (WTRU) in a CELL_PCH and URA_PCH states,the method comprising: a WTRU determining whether a serving radionetwork controller (SRNC) has an enhanced forward access channel (FACH)capability of supporting reception of a high speed downlink sharedchannel (HS-DSCH) in a CELL_FACH state; and the WTRU performingconfiguration to receive a message over an HS-DSCH based on thecapability of the SRNC.
 26. The method of claim 25 wherein the WTRU, inan IDLE mode, determines that the SRNC to which the WTRU is attemptingto connect has the enhanced FACH capability if a selected cell has theenhanced FACH capability.
 27. The method of claim 25 wherein the WTRU,in a radio resource control (RRC) connected mode, determines that theSRNC has the enhanced FACH capability if the WTRU has configured itselffor reception of HS-DSCH in CELL_FACH state at any point throughout alife of the RRC connection with the SRNC.
 28. The method of claim 25wherein the WTRU, in a radio resource control (RRC) connected mode,determines that the SRNC has the enhanced FACH capability if the WTRUhas been configured to operate using any third generation partnership(3GPP) Release 7 feature while connected to the SRNC.
 29. The method ofclaim 25 wherein the WTRU obtains the capability of the SRNC viadedicated radio resource control (RRC) signaling.
 30. The method ofclaim 25 wherein the WTRU obtains the capability of the SRNC viabroadcast signaling that provides a list of radio network controllers(RNCS) that support enhanced CELL_FACH.
 31. A method for paging awireless transmit/receive unit (WTRU) in a CELL_PCH and URA_PCH states,the method comprising: a WTRU receiving a message indicating whether theWTRU should support an enhanced paging channel (PCH) capability ofreceiving a high speed downlink shared channel (HS-DSCH) in CELL_PCH andURA_PCH states; and the WTRU performs configuration for receiving apaging message based on the message.
 32. The method of claim 31 whereinthe WTRU monitors the S-CCPCH when a serving radio network subsystem(SRNS) does not support enhanced PCH.
 33. The method of claim 32 whereinthe WTRU monitors the S-CCPCH when the SRNS supports enhanced PCH butHS-DSCH paging system information is not broadcast in a cell.
 34. Themethod of claim 31 wherein the configuration is valid throughout a lifeof a connection to a serving radio network controller (SRNC).
 35. Themethod of claim 34 further comprising: recognizing that serving radionetwork subsystem (SRNS) relocation takes place; and reevaluatingsupport for enhanced PCH capability when SRNS relocation takes place.36. A method for paging a wireless transmit/receive unit (WTRU) in aCELL_PCH and URA_PCH states, the method comprising: a WTRU determiningwhether to monitor a paging channel (PCH)/secondary common controlphysical channel (S-CCPCH) or a high speed downlink shared channel(HS-DSCH) to receive a paging message in one of CELL_PCH and URA_PCHstates based on capabilities of the WTRU and a cell and a conditionrelated to a reception method that the WTRU used during a previouscommunication with a network in a current radio resource control (RRC)connection; and the WTRU performs configuration for receiving the pagingmessage based on the determination.
 37. The method of claim 36 whereinthe WTRU monitors only the HS-DSCH in CELL_PCH and URA_PCH states if theWTRU has sent an RRC message, since beginning of the RRC connection,with a radio network controller (RNC) that supports an enhanced PCHcapability.
 38. The method of claim 36 wherein the WTRU monitors thePCH/S-CCPCH from the time when the WTRU successfully sends an RRCmessage to an RNC that does not support the enhanced PCH capability. 39.The method of claim 36 wherein the WTRU monitors the PCH/S-CCPCH for thepaging message if the WTRU receives information indicating that aserving radio network controller (SRNC) does not support an enhancedPCH.
 40. A method for paging a wireless transmit/receive unit (WTRU) ina CELL_PCH and URA_PCH states, the method comprising: receiving a URAUPDATE message including an indication indicating an enhanced pagingchannel (PCH) capability of receiving a high speed downlink sharedchannel (HS-DSCH) in CELL_PCH and URA_PCH states; determining acapability mismatch in a WTRU and a serving radio network controller(SRNC); sending a relocation request message to initiate serving radionetwork subsystem (SRNS) relocation; performing SRNS relocation; andsending a URA UPDATE CONFIRM message to the WTRU over an HS-DSCH. 41.The method of claim 40 wherein the capability mismatch is detected by adrift radio network controller (DRNC) and the SRNS relocation isinitiated by the DRNC.
 42. The method of claims 40 wherein thecapability mismatch is detected by the SRNC and the SRNS relocation isinitiated by the SRNC.
 43. A wireless transmit/receive unit (WTRU)configured to receive a paging message in a CELL_PCH and URA_PCH states,the WTRU comprising: a controller for sending an indication indicatingan enhanced paging channel (PCH) capability of receiving a high speeddownlink shared channel (HS-DSCH) in CELL_PCH and URA_PCH states; and atransceiver for receiving a message over an HS-DSCH.
 44. The WTRU ofclaim 43 wherein the controller is configured to send a secondindication indicating an enhanced forward access channel (FACH)capability of receiving the HS-DSCH in a CELL_FACH state.
 45. The WTRUof claim 43 wherein the indication is included in one of a CELL UPDATEmessage, a URA UPDATE message, and a UTRAN MOBILITY INFORMATION CONFIRMmessage.
 46. The WTRU of claim 45 wherein the CELL UPDATE message andthe URA UPDATE message including the indication are sent if capabilitiesof a new cell are different than capabilities of an old cell.
 47. TheWTRU of claim 45 wherein the URA UPDATE message including the indicationis sent if a new cell supporting enhanced PCH is controlled by acontrolling radio network controller (CRNC) that is different than aserving radio network controller (SRNC).
 48. The WTRU of claim 47wherein the controller determines that the CRNC is different than theSRNC if an SRNC identify in a UTRAN radio network temporary identity(U-RNTI) is different than 12 most significant bits of a cell identity.49. The WTRU of claim 45 wherein the controller sends the URA UPDATEmessage including the indication if a WTRU has roamed from a cell thatdoes not support enhanced FACH and/or enhanced PCH to a cell thatsupports enhanced FACH and/or enhanced PCH.
 50. The WTRU of claim 45wherein the controller sends the URA UPDATE message including theindication if a new cell is controlled by a controlling radio networkcontroller (CRNC) that is different from a CRNC that controlled aprevious cell.
 51. The WTRU of claim 45 wherein the controller sends theURA UPDATE message including the indication if the WTRU is unaware if aserving radio network controller (SRNC) to which it is connectedsupports enhanced FACH and/or enhanced PCH.
 52. The WTRU of claim 45wherein the UTRAN MOBILITY INFORMATION CONFIRM message is sent inresponse to an indication that serving radio network subsystem (SRNS)relocation has taken place.
 53. The WTRU of claim 43 wherein thecontroller determines if a serving radio network controller (SRNC) towhich the WTRU is connected supports enhanced PCH by maintaining aninternal variable indicating SRNC enhanced FACH and/or PCH capability.54. The WTRU of claim 53 wherein the internal variable is set to FALSEif any one of following conditions is satisfied: if a new UTRAN radionetwork temporary identity (U-RNTI) is assigned to the WTRU, if a WTRUradio network controller (RRC) state changes from CELL_DCH to URA_PCH,if a WTRU RRC state changes from CELL_FACH to URA_PCH, if a WTRU RRCstate changes from CELL_PCH to URA_PCH, if a WTRU RRC state changes fromURA_PCH to CELL_PCH or CELL_FACH or CELL_DCH, if the WTRU receives anRRC message in a cell that does not support enhanced PCH and/or enhancedFACH and a new U-RNTI is assigned, and if the WTRU receives an RRCmessage while in CELL_DCH state and a new U-RNTI is assigned.
 55. TheWTRU of claim 53 wherein the internal variable is set to TRUE when atleast one of following conditions is satisfied: if the WTRU successfullyreceives a URA UPDATE CONFIRM message after having triggered a transferof a URA UPDATE message including the indication, if the WTRUsuccessfully receives a URA UPDATE CONFIRM message after havingtransferred a URA UPDATE message in a cell that supports enhanced FACHand/or enhanced PCH, if the WTRU successfully receives a CELL UPDATECONFIRM message after having transferred a CELL UPDATE message in a cellthat supports enhanced FACH and/or enhanced PCH, if the WTRU roams to acell that supports enhanced FACH and/or enhanced PCH and the cell iscontrolled by a serving radio network controller (SRNC) to which theWTRU is connected, and if the WTRU initiates an RRC connection in a cellthat supports enhanced FACH and/or enhanced PCH.
 56. An apparatus forpaging a wireless transmit/receive unit (WTRU) in a CELL_PCH and URA_PCHstates, the apparatus comprising: a controller for receiving anindication indicating whether the WTRU has an enhanced paging channel(PCH) capability of receiving a high speed downlink shared channel(HS-DSCH) in CELL_PCH and URA_PCH states and page the WTRU based on theindication; and a transceiver for sending a paging message.
 57. Theapparatus of claim 56 wherein the indication is included in a PAGINGREQUEST message from a serving radio network controller (SRNC).
 58. Theapparatus of claim 57 wherein the indication is present in the PAGINGREQUEST message only if the WTRU has an enhanced PCH capability.
 59. Theapparatus of claim 57 wherein the indication is provided independentlyof a paging area choice.
 60. The apparatus of claim 57 wherein theindication is provided only if a paging area choice is UTRAN routingarea (URA).
 61. The apparatus of claim 56 wherein an HS-DSCH PAGINGREQUEST message is used to page the WTRU over an HS-DSCH, and a PAGINGREQUEST message is used to page the WTRU over a PCH/secondary commoncontrol physical channel (S-CCPCH).
 62. The apparatus of claim 57wherein if the indication is not present in the PAGING REQUEST message,the paging message is sent over a PCH/secondary common control physicalchannel (S-CCPCH).
 63. The apparatus of claim 57 wherein if theindication is not present in the PAGING REQUEST message, the pagingmessage is sent over both an HS-DSCH and a PCH/secondary common controlphysical channel (S-CCPCH).
 64. An apparatus for paging a wirelesstransmit/receive unit (WTRU) in a CELL_PCH and URA_PCH states, theapparatus comprising: a transceiver for receiving a PAGING REQUESTmessage for the WTRU; and a controller for paging the WTRU over both ahigh speed downlink shared channel (HS-DSCH) and a paging channel(PCH)/secondary common control physical channel (S-CCPCH) if acapability of the WTRU of receiving an HS-DSCH in CELL_PCH and URA_PCHstates is not known.
 65. A wireless transmit/receive unit (WTRU) forreceiving a paging message in a CELL_PCH and URA_PCH states, the WTRUcomprising: a transceiver for receiving and decoding a paging indicationover a paging indicator channel (PICH) and receiving a paging message;and a controller for controlling the transceiver to monitor both a highspeed downlink shared channel (HS-DSCH) and a paging channel(PCH)/secondary common control physical channel (S-CCPCH) in one ofCELL_PCH and URA_PCH states.
 66. The WTRU of claim 65 wherein thecontroller controls the transceiver to monitor both the HS-DSCH and thePCH/S-CCPCH if a serving cell supports paging over HS-DSCH.
 67. The WTRUof claim 66 wherein the controller controls the transceiver to monitorboth the HS-DSCH and the PCH/S-CCPCH if the WTRU has roamed from a cellthat does not support enhanced CELL_FACH to a cell that supportsenhanced CELL_FACH.
 68. The WTRU of claim 66 wherein the controllercontrols the transceiver to monitor both the HS-DSCH and the PCH/S-CCPCHif the WTRU is unaware of capabilities of a serving radio networkcontroller (SRNC) to which the WTRU is connected.
 69. A wirelesstransmit/receive unit (WTRU) for receiving a paging message in aCELL_PCH and URA_PCH states, the WTRU comprising: a transceiver; and acontroller for determining whether a serving radio network controller(SRNC) has an enhanced forward access channel (FACH) capability ofsupporting reception of a high speed downlink shared channel (HS-DSCH)in a CELL_FACH state and configuring the transceiver to receive amessage over an HS-DSCH based on the capability of the SRNC.
 70. TheWTRU of claim 69 wherein the controller, in an IDLE mode, determinesthat the SRNC to which the WTRU is attempting to connect has theenhanced FACH capability if a selected cell has the enhanced FACHcapability.
 71. The WTRU of claim 69 wherein the controller, in a radioresource control (RRC) connected mode, determines that the SRNC has theenhanced FACH capability if the WTRU has configured itself for receptionof HS-DSCH in CELL_FACH state at any point throughout a life of the RRCconnection with the SRNC.
 72. The WTRU of claim 69 wherein thecontroller, in a radio resource control (RRC) connected mode, determinesthat the SRNC has the enhanced FACH capability if the WTRU has beenconfigured to operate using any third generation partnership (3GPP)Release 7 feature while connected to the SRNC.
 73. The WTRU of claim 69wherein the controller obtains the capability of the SRNC via dedicatedradio resource control (RRC) signaling.
 74. The WTRU of claim 69 whereinthe controller obtains the capability of the SRNC via broadcastsignaling that provides a list of radio network controllers (RNCS) thatsupport enhanced CELL_FACH.
 75. A wireless transmit/receive unit (WTRU)for receiving a paging message in a CELL_PCH and URA_PCH states, theWTRU comprising: a transceiver; and a controller for receiving a messageindicating whether the WTRU should support an enhanced paging channel(PCH) capability of receiving a high speed downlink shared channel(HS-DSCH) in CELL_PCH and URA_PCH states and configuring the transceiverfor receiving a paging message based on the message.
 76. The WTRU ofclaim 75 wherein the controller controls the transceiver to monitor theS-CCPCH when a serving radio network subsystem (SRNS) does not supportenhanced PCH.
 77. The WTRU of claim 76 wherein the controller controlsthe transceiver to monitor the S-CCPCH when the SRNS supports enhancedPCH but HS-DSCH paging system information is not broadcast in a cell.78. The WTRU of claim 75 wherein the configuration is valid throughout alife of a connection to a serving radio network controller (SRNC). 79.The WTRU of claim 78 wherein the controller recognizes that servingradio network subsystem (SRNS) relocation takes place and reevaluatessupport for enhanced PCH capability when SRNS relocation takes place.80. A wireless transmit/receive unit (WTRU) for receiving a pagingmessage in a CELL_PCH and URA_PCH states, the WTRU comprising: atransceiver; and a controller for determining whether to monitor apaging channel (PCH)/secondary common control physical channel (S-CCPCH)or a high speed downlink shared channel (HS-DSCH) to receive a pagingmessage in one of CELL_PCH and URA_PCH states based on capabilities ofthe WTRU and a cell and a condition related to a reception method thatthe WTRU used during a previous communication with a network in acurrent radio resource control (RRC) connection and configures thetransceiver for receiving the paging message.
 81. The WTRU of claim 80wherein the controller configures the transceiver to monitor only theHS-DSCH in CELL_PCH and URA_PCH states if the WTRU has sent an RRCmessage, since beginning of the RRC connection, with a radio networkcontroller (RNC) that supports an enhanced PCH capability.
 82. The WTRUof claim 80 wherein the controller configures the transceiver to monitorthe PCH/S-CCPCH from the time when the WTRU successfully sends an RRCmessage to an RNC that does not support the enhanced PCH capability. 83.The WTRU of claim 80 wherein the controller configures the transceiverto monitor the PCH/S-CCPCH for the paging message if the controllerreceives information indicating that a serving radio network controller(SRNC) does not support an enhanced PCH.
 84. An apparatus for paging awireless transmit/receive unit (WTRU) in a CELL_PCH and URA_PCH states,the apparatus comprising: a transceiver; and a controller for receivinga URA UPDATE message including an indication indicating an enhancedpaging channel (PCH) capability of receiving a high speed downlinkshared channel (HS-DSCH) in CELL_PCH and URA_PCH states, determining acapability mismatch in a WTRU and a serving radio network controller(SRNC), sending a relocation request message to initiate serving radionetwork subsystem (SRNS) relocation, performing SRNS relocation, andsending a URA UPDATE CONFIRM message to the WTRU over an HS-DSCH.